Gyromagnetic compass controlling means



y 1945- -F. D. BRADDO N GYRO MAGNETIC COMPASS CONTROLLING MEANS Filed Jan. 19, 1943 V 2 Sheets-Shee1i l INVENTOR E D. BRADD Muzv Ma 15, 1945. B A DON 2,375,764.

GYRO MAGNETIC COMPASS GONTROLLINGMEANS Filed Jan. 19, 1943 2 Sheets-Sheet 2 FIG. 5

FIG.

INVENTdR E D. BRADDON movement about a vertical of the outer casing 30, the

Patented May 15, 1945 Frederick D. Braddon, Babylon, .N. Y., assignor to Sperry Gyroscope Company, Inc., N. Y., a corporation of NewYork Brooklyn,

Application January 19, 1943, Serial No. 472,910

:4 Claims. (01. 33-222) This invention generally relates to gyroscopic controlling means and more particularly is directed to a thermal meansfor effecting selective operation of a torque exerting device.

The primary feature of the present invention resides in the provision of a thermally responsive difierential selector for controlling the operation of a torque exerting device about the axis of the rotor bearing case of a gyroscopic instrument of the gyro magnetic compass type.

Other features and structural details of the invention will be apparentfrom the following description when read in relation to the accompanying drawings wherein,

Fig. 1 is a side elevation view of a gyroscopic instrument of the gyro magnetic compass type constructed in accordance with the teaching of the present invention, the ment being shown in section.

Fig. 2 is a detail cross-section view of the rotor bearing case of the instrument shown in Fig. 1, the view being taken on line 2-2 in that figure.

Figs. 3 and 4 are detail circuit diagrams. Fig. 5 is a section of the rotor bearing case taken on line 5-5, in Fig. 1.

Fig. 6 is a view similar. to Fig. 5 taken on line 6-6, in Fig. l. l

Fig. 7 is a sectionview taken on line 7-1, in

r Fig. 5. I

Fig. 8 is a section view taken on line 8-8, in

Fig. 5. a Figs. 9 and 10 are detail sectional views showing the pivotal mountings ofthe respective torque controlling vanes on the rotor case.

Fig. 11 is a section view similar to Fig. 2 showing a modified form of invention, and

Fig. 12 is a view similar to Fig. 5 of the rotor bearing case construction.

With reference to Fig. 1, the conventional parts of the gyro magnetic compass instrument shown in the drawings include an outer casing 30 within which a vertical ring 3|is suitably mounted for axis. This mounting may be provided by bearings 32 and 33 located in the upper and lower walls of the outer casing, respectively. Ring 3| controls the movement of a conventional type of compass card 34 situated ad- J'acent a transparent portion 35 of the front wall card being mounted on a shaft 36 that is moved by means of the meshed crown and bevel gears 37 and 38, respectively. In the construction shown, the bevel gear 38 forms the base of the vertical ring 3|. Thrust bearing 40 in the base of the outer casing takes bearings 41 and 48.

casing of the instrua indicated at 4|.

the gravitational loadfof the weight of the vertical ring 3| and the gyroscopic parts mounted thereon.

With reference also to Figs. 2 and5 through 8, inclusive, the rotor bearing case of the illustrated gyro magnetic compass instrument is generally The case in the present instance is mounted in a conventional manner between the upwardly extending arms of the'vertical ring 3| by means of trunnions42 and 43 and suitable bearings 42' and43'. The thus defined tilt or horizontal axis of the case is located in mutually perpendicular relation to the axis of the ring 3|. Within the case 4|, as shown in Fig. 2, a, gyro rotor 45 is fixedly mounted on shaft 45 having journal forming ends that engage the spaced Gyro rotor45 as shown may be a non-inductive rotor of the type more particularly .shown and described in my copending application Serial No. 434,771, 1942;on this subject matter.

The spin axis of the rotor 45 normally lies in a horizontal. plane that includesthe axis of the casing by way of case! the rotor axis and case axis beingmutual 1y perpendicular. The gyro rotor is shown as being withdrawn from the outlet 49 by means of a suitable suction means (not shown). Atmospheric air is admitted to the case 4| by way of filter 50, hollow trunnion 5|, channel 52 in the vertical ring 3|, hollow trunnion 43 to the circular passageways 53 formed in the case- Nozzle forming openings .54 direct the air in the passageways to impinge the same on the buckets 55 of the rotor 45.

Themeans provided in this form of the inventionfor exerting a torque about the horizontal axis of the case: to cause precession of the ring is pneumatic. In this connection, the air withdrawn from the interior of the rotor bearing case is employed to obtain the torque. The air within the case dischargesthrough exhaust ports 58 and 59 in the case slot openingsor ports 60 and 6|, Figs, 1, 2,7 and 8.

Openings 6D and 6| are situatedthe same radial.

distance above and below the tilt axis of the case 4| so that the air discharging therefrom into the casing 3E1 normally exerts equal and opposite torque about the axis of the case. The continuous air jets issuing from the openings 63 and 6| in the case 4| maybe obtained in other manners: now knownto the art if so desired.

Further, theimproved gyro magnetic compass instrument includes a direction maintaining means or azimuth standard of position which is filed March 14,

which terminate in the narrower theopem'ng or port 6i in. the case-4|.

instrumental in maintaining the gyro case-ina properly oriented position relative to the earth.

As shown, such means comprises a magnetic compass having a sensitive element mounted on the case. The sensitive element shown in the drawings is a magnet 63 which is mounted for pivotal movement about a vertical axis on the top of the rotor bearing case M. As particularly shown in Figs. 1, 2 and 5, bar 63 is mounted on a shaft 64; contained in a frame 65 situated on" the top of the case. A controller. is. also. provided which operates responsive to" angular dis-, a

placement of the ring from a normal position in azimuth. This controlleir'includsa segmental.

vane 66 which is fixed to the shaft fifand i's' suitably counterbalanced by a weight piecelif'." As shown in Fig. 5, the vane is positioned. in'-a.Zi--

muth by means of the magnet bar 63. The opmagnetic compass instrument may be obtained in anyv manner now well known in the art, the same consequently not being shown herein.

In the operation of the described type of gyro magnetic compass, when the ring 3| (ports 68 and 69 in the case 4|) and vane 66 moves to a position of angular displacement other than normal, one of the ports 68, 69 is opened and. the other is closed. If, for example, port 68 is Opened and port 69 is closed, the air passing through passageway 10 from the interior of the case does not.

divide and flow in equal volume through chanpositely disposed straight edges of the segmental vane 66 normally intercept equal portions of the ainjetsissuing from two orts 68and6'9' situated inthe. top of the case. The position determining ports 68 and 69 of the case are smaller than ports 60 and 6'1 and are situatedlrelatively' close to the axis of the case so that the torqueefiect on the case from the reaction of the air issuing, from thesame is negligible. Air is drawn through the ports 68 and 69' and into the evacuated casing 39 by the previously mentioned suction means. Air supplied the ports 68 and 69' is obtained from the interior of the rotor bearingcase by way of passageway 62, Fig. 2, which leads to a circular port.

T0. A valve 'Il may be employed to control the volume of air passing through the passageway 62".

As shown in Figs. 7 and 8, port lllleads to two oppositely disposed channels 12" andl3 provided by arranging contiguous grooves in'the'end'plate M of the'case' 4| and in a special cover plate 15 which is'fixedly mounted on the case in a suitable manner. Channels 12 and'13 lead to the opposite passageways 16 and H in the topof the case M in which the'ports 68' and 69 are located. In" accordance with the teaching of the present.

invention, thermal means are employed which respond to the control of the described controller to differentially'effect operation or the torque exerting'means. As shown, thethermal'means'is" provided'by a differentially-cooled pair ofheated wirestil and-8 I' located in the-respective channels 12 and 13. The ends of the'wires 86" and 81 are fixed to suitable terminal blocks 82 and 6 3; respectively, mounted on the cover plate 15'. Wires 80' and El are formed of an electrically conductive material having a relatively high coeflicientofexpansion and heat radiation. As shown in Fig. 4, the wires may be heated by supplying the same withelectrical energy of asuitable character: such. as-a battery. The respective wires extend. in. this instance, in a V shape within-the channels 12 and 13.

latedpin 86 at its apex forming portion. Pin 86: controls a rocker member on the case M which positions a vane 37 so WireBll similarly engages a pin 84; Fig. 10, which positions the vane 85 so that it normally bisects the Withrei'erenc'e to Fig. 9 particular1y, wire -8l' is connected to. an insuthat it normally. bisects.

and 8 'I', Figs;; 9 andIO. this i of theair moves through channel 12.

nels I2 and 13. In this event, the air in channel 13: issubstantially blocked and substantially all Wire 80 consequentiy expands permitting the vane 85 toassumea lower osition as viewed in Fig. 1

and more air to issue from the port 60. Wire 8! contractsdue to the cooling effect of the additional air passing through channel. 12 which raises the vane 81 as viewed in Fig. 1 to further restrict the effective size of theport 6i and reduce the volume of air passin therethrough. The described type of thermal means-operates in response to the controller to control the torque exerting m'ean'swhich in this instance is pneumatic to process .the ring so that the core is re,- stored to its normal position with relation to the standard of position.

Figs. 3, l1 and 12; illustrate a modification of the invention in which gravitationally responsive" means are employed to" exert the torque torques about the about the horizontal axis of the case 4!. Such means are shown in Fig. .11; in the form ,of two weight members 99 and 9! whichareadapt'edto.

slide in a channelforme'd in the base of the case M. Theweights are located in a: passageway 92' that receives air from a central portigii from the interior of the rotor be'aringcase. The air received in passageway 92" normally divides, and.

equal parts of the same moveto the right and left'as viewed in Fig.- 11 through the passageway 92. The air moving to the'right in the figure passes through-a1 channel 9 4at one endiot the case, communicatin channel 95' and" then through port 96in the top' of the case. The

air moving to the left, as viewed in the figure,

passes through channel 91', communicating channel 98 and then port 99 in the top of the'case;

The air passingthrough the ports iltand 99impinges on a fixed shield Hill on the frame 65 and consequently does not affect the normal operation of the magnetic compass. The vane Hil which is positioned-by the magnet 63'n'orma1ly bisects the air issuing from theoppositelydisposed ports 96'- and" 99', the function of the ports being similar to that previously described. Ports 96 and 99 are situated-on tlietilt axis of the case and. consequently exert no torque about this'a'xis of the case. A central fixed insulating post I02 is locat'ed in the passageway 92; the same providing a mounting for two electrical energy conducting resistance wires I63 and W4 which are secured to. the respective weights 9!! and 912 The wires-position the weights and are electrically heated-by means oiza battery and'circuit there for as shown in Fig. 3. The wires are'coristructedof suflicient rigidityrto definitely position the wcights with respect to" the post I62. The con trolled air flow over. the wires. differentially effects. movement of the'weights towards or away from the post as viewed in Fig; lLto control the operation of thegravitational torque onthexcase M in a manner that restores the parts to their normal position.

the earths magnetic As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompany:

ing drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In agyro-magnetic compass-a gyro rotor case mounted with freedom about a vertical axis and a horizontal axis, an element responsive to I for movement about air flow means on said case responsive to angular displacement between said element and said case about the respective vertical axes thereof, a pair of heated wires onsaid case difierentially field mounted on saidcase a vertical axis, differential cooled by said air flow means, and means for exerting a torque about the horizontal'axis of said case differentially controlled by the expansion and contraction of said wires. l 1 2. A gyro-magnetic compass as claimed in claim 1, in which said torque exerting means comprises air jet means having shutters pivotally mounted on said said wires. t i 3. Means for exerting a precession inducing case and positioned by for movement about a vertical axis, a differential air flow controller responsive to departure of the magnet and rotor case from a predeter- 1 mined azimuthal relation, thermostatic means on said case differentially cooled by said air flow controller, a pair of shutters pivotally mounted on the rotor case connected to be operated by said thermostatic means, and air jet means on said case-difierentially intercepted by said shutters whereby a torque is exerted on said rotor case to cause precession restoring said relation.

4. Means for exerting a precession inducing torque about the horizontal axis of the gyro rotor case of a gyro-magnetic compass instrument comprising a laterallyjshiftable mass on said case,

torque about the horizontal axis of thegyro rotor case of a gyro-magnetic compass instrument 3 comprising a magnet mounted on the gyro case 

